Power-Up Display; Power-Up Sequence - HP 400 Series Servicing Manual

4.7.2

Power-Up Display

When you turn your system unit on after the first time and the default functional mode
is Hewlett-Packard, the Boot ROM invokes the power-up display and starts its self-test.
The Power-Up Display looks like this:
Copyright 1990,
Hewlett-Packard Company,
All Rights Reserved.
Series 400 BOOTROM, Rev. 1, 5 Jun 90
MD 12 (date code)
Bit-Mapped video
MC680n0 Processor
System Search Mode
RESET to Power-up
4.7.3

Power-Up Sequence

When you turn on the system unit, the CPU executes a power-up sequence of events
before an operating system is booted. This is required to initialize and test hardware
to make sure the system unit is ready to boot an operating system. The 29 steps of the
power-up sequence are
1. Test the CPU chip.
2. Turn on test LEDs.
3. Test the top 16 KB of RAM.
4. Set up data structures.
5. Load configuration data from EEPROMs.
6. Search for any boot extension ROMs and call any valid ones.
7. Determine processor type.
8. Initialize and test system/processor board timer.
9. Look for a RAM/monitor debugger.
10. Reset all I/O.
11. Initialize the video circuits.
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.
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Fault Isolation 4-33